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| author | Steven Bosscher <steven@gcc.gnu.org> | 2012-12-05 23:16:52 +0000 |
|---|---|---|
| committer | Steven Bosscher <steven@gcc.gnu.org> | 2012-12-05 23:16:52 +0000 |
| commit | aeb9f7cf3ce55e65fb9f435702e20c7c3f37d7e5 (patch) | |
| tree | 7daa076305a95e822e50b52025fa432bc497750f /gcc/doc/tm.texi | |
| parent | 833fe7dadc06faaeefb7812a69dcc9a178543184 (diff) | |
| download | gcc-aeb9f7cf3ce55e65fb9f435702e20c7c3f37d7e5.zip gcc-aeb9f7cf3ce55e65fb9f435702e20c7c3f37d7e5.tar.gz gcc-aeb9f7cf3ce55e65fb9f435702e20c7c3f37d7e5.tar.bz2 | |
tm.texi.in (TARGET_CLASS_LIKELY_SPILLED_P): Update documentation.
* doc/tm.texi.in (TARGET_CLASS_LIKELY_SPILLED_P): Update documentation.
* doc/tm.texi: Regenerate.
* regs.h (REG_LIVE_LENGTH): Update comments to not refer to no longer
existing files global.c and local-alloc.c.
* regmove.c (copy_src_to_dest): Likewise.
* function.h (struct rtl_data): Likewise.
* ira-color.c (allocno_priority_compare_func): Likewise.
* regstat.c (regstat_compute_ri): Likewise.
* config/epiphany/epiphany.h, config/vax/vax.h, config/cris/cris.h,
config/h8300/h8300.h, config/alpha/alpha.h, config/sparc/sparc.h,
config/rs6000/rs6000.h, config/pdp11/pdp11.h, config/pa/pa.h,
config/v850/v850.h, config/mn10300/mn10300.h, config/m32r/m32r.h,
config/i386/i386.h, config/mcore/mcore.h, config/sh/sh.h,
config/arm/arm.h (REGNO_OK_FOR_BASE_P): Likewise.
From-SVN: r194229
Diffstat (limited to 'gcc/doc/tm.texi')
| -rw-r--r-- | gcc/doc/tm.texi | 16 |
1 files changed, 7 insertions, 9 deletions
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi index f981964..3ab9987 100644 --- a/gcc/doc/tm.texi +++ b/gcc/doc/tm.texi @@ -2834,15 +2834,13 @@ registers of @var{rclass} are needed for spill registers. The default version of this target hook returns @code{true} if @var{rclass} has exactly one register and @code{false} otherwise. On most machines, this -default should be used. Only use this target hook to some other expression -if pseudos allocated by @file{local-alloc.c} end up in memory because their -hard registers were needed for spill registers. If this target hook returns -@code{false} for those classes, those pseudos will only be allocated by -@file{global.c}, which knows how to reallocate the pseudo to another -register. If there would not be another register available for reallocation, -you should not change the implementation of this target hook since -the only effect of such implementation would be to slow down register -allocation. +default should be used. For generally register-starved machines, such as +i386, or machines with right register constraints, such as SH, this hook +can be used to avoid excessive spilling. + +This hook is also used by some of the global intra-procedural code +transformations to throtle code motion, to avoid increasing register +pressure. @end deftypefn @deftypefn {Target Hook} {unsigned char} TARGET_CLASS_MAX_NREGS (reg_class_t @var{rclass}, enum machine_mode @var{mode}) |